1. Field of the Invention
The invention relates to a system comprising an apparatus and at least one remote control, said remote control comprising a transmitter for transmitting control data to the apparatus and collision preventing means for preventing collision between said control data and further control data transmitted by a further remote control.
The invention also relates to a remote control for use in the above system.
The invention also relates to a method of transmitting control data from a remote control to an apparatus, comprising a step of preventing collision between said control data and further control data transmitted by a further remote control.
2. Description of the Related Art
Recently there has been an increasing demand for simultaneous use of two or more remote controls to control a single apparatus. For example, multiple remote controls may be used for controlling a multi-player game, or for allowing multiple viewers of an interactive TV show to key in answers to questions and compare the results and reaction times. In such situations, it will often occur that two users operate their remote control at the same time, causing collision between signals transmitted from the respective remote controls.
An example of a system of the type defined in the opening paragraph is known from U.S. Pat. No. 5,663,716. The known system comprises an apparatus and a plurality of remote controls for controlling said apparatus. Collision between signals of the remote controls is avoided by transmitting each message multiple times, separated by pauses which are longer than the message time itself. Using this scheme, it can be guaranteed that at least one copy of the data will be received by the apparatus without having any interference with messages originating from other remote controls.
A disadvantage of the known system is that the repeated transmission of each message is inefficient in terms of time and power consumption. Each transmission consumes battery power, which is an important drawback, particularly for (wireless) remote controls. Furthermore, each transmission takes a certain time, which could have been used for transmitting another message from the same or another remote control. Especially in highly interactive applications, such as action games, this is a severe drawback.